Development and Validation of an Abridged Version of the REVEAL 2.0 Risk Score Calculator, REVEAL Lite 2, for Use in Patients With Pulmonary Arterial Hypertension

Interest of TAPSE/sPAP ratio for noninvasive pulmonary arterial hypertension risk assessment

BACKGROUND

Although ventriculoarterial coupling is associated with better survival in pulmonary arterial hypertension (PAH), existing PAH risk assessment method has not considered echocardiographic criteria of right ventricular to pulmonary artery coupling. We aimed to test the prognostic value of the echocardiographic tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/sPAP) ratio for noninvasive PAH risk assessment.

METHODS

We retrospectively studied a cohort of 659 incident PAH patients from 4 independent French PH centers (training cohort: n = 306, validation cohort n = 353) who underwent follow-up TAPSE/sPAP measurement in addition to previously validated noninvasive risk stratification variables. The primary composite outcome was 3-year all-cause mortality or lung transplantation from re-evaluation.

RESULTS

Mean age was 55 ± 17 years-old with a majority of female (66%). The three main PAH causes were connective tissue disease (26%), idiopathic (24%) and porto-pulmonary (19%). The primary composite outcome occurred in 71 (23%) patients. Multivariable Cox regression analysis retained 3 noninvasive low-risk criteria as associated with the primary composite outcome: NYHA I-II (p = 0.001), NTproBNP <300 ng/L or BNP <50 ng/L (p = 0.004), and TAPSE/sPAP >0.33 mm/mmHg (p = 0.004). The more the low-risk criteria achieved at follow-up, the better the event-free survival both in the training and validation cohort (log-rank p < 0.001). In the training cohort, the c-index for these 3 criteria, for COMPERA 2.0 and for the noninvasive French Pulmonary Hypertension Network method were 0.75, 95%CI(0.70-0.82), 0.72 95%CI(0.66-0.75), 0.71 95%CI(0.62-0.73), respectively.

CONCLUSION

The 3 following dichotomized low-risk criteria: TAPSE/sPAP >0.33 mm/mmHg, NYHA I-II and NTproBNP <300 ng/L or BNP <50 ng/L allow to identify low-risk PAH patients at follow-up.

Cardiac Effort to Compare Clinic and Remote 6-Minute Walk Testing in Pulmonary Arterial Hypertension

BACKGROUND

The SARS-CoV-2 pandemic has limited objective physiologic assessments. A standardized remote alternative is not currently available. "Cardiac effort" (CE), that is, the total number of heart beats divided by the 6-min walk test (6MWT) distance (beats/m), has improved reproducibility in the 6MWT and correlated with right ventricular function in pulmonary arterial hypertension.

RESEARCH QUESTION

Can a chest-based accelerometer estimate 6MWT distance remotely? Is remote cardiac effort more reproducible than 6MWT distance when compared with clinic assessment?

STUDY DESIGN AND METHODS

This was a single-center, prospective observational study, with institutional review board approval, completed between October 2020 and April 2021. Group 1 subjects with pulmonary arterial hypertension, receiving stable therapy for > 90 days, completed four to six total 6MWTs during a 2-week period to assess reproducibility. The first and last 6MWTs were performed in the clinic; two to four remote 6MWTs were completed at each participant's discretion. Masks were not worn. BioStamp nPoint sensors (MC10) were worn on the chest to measure heart rate and accelerometry. Two blinded readers counted laps, using accelerometry data obtained on the clinic or user-defined course. Averages of clinic variables and remote variables were used for Wilcoxon matched-pairs signed rank tests, Bland-Altman plots, or Spearman correlation coefficients.

RESULTS

Estimated 6MWT distance, using the MC10, correlated strongly with directly measured 6MWT distance (r = 0.99; P < .0001; in 20 subjects). Remote 6MWT distances were shorter than clinic 6MWT distances: 405 m (330-464 m) vs 389 m (312-430 m) (P = .002). There was no difference between in-clinic and remote CE: 1.75 beats/m (1.48-2.20 beats/m) vs 1.86 beats/m (1.57-2.14 beats/m) (P = .14).

INTERPRETATION

Remote 6MWT was feasible on a user-defined course; 6MWT distance was shorter than clinic distance. CE calculated by chest heart rate and accelerometer-estimated distance provides a reproducible remote assessment of exercise tolerance, comparable to the clinic-measured value.

Portopulmonary Hypertension in Nontransplanted Patients: Results of the Largest US Single-Institution Registry

OBJECTIVE

To explore clinical characteristics, risk profiles, and outcomes of patients with portopulmonary hypertension (PoPH) who have contraindications to liver transplant (LT).

METHODS

From the largest US single-institution registry of patients with PoPH, we analyzed 160 patients who did not receive LT between 1988 to 2019. Pulmonary arterial hypertension (PAH)-pertinent characteristics, hemodynamic features, treatments, and risk stratification were compared at baseline, first follow-up visit, and censor/death time.

RESULTS

Median survival for the entire cohort was 27.5 months from the diagnosis of PoPH. Overall survival was 89%, 77%, 51%, and 38% at 6 months, 1 year, 3 years, and 5 years, respectively. Survival was significantly affected by the severity of liver disease (P<.001). Most patients received PAH-specific therapies (136 [85%]), predominantly monotherapy (123 [77%)]. With treatment, significant improvements were noted in World Health Organization functional class (P=.04), 6-minute walk distance (P<.001), right ventricular function (P<.001), pulmonary vascular resistance (P<.001), and Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) Lite 2 score (P=.02) univariately. Per European Society of Cardiology risk stratification, no patient met full criteria for low risk at baseline or at follow-up. In a multivariate Cox risk model, 6-minute walk distance, right atrial pressure, pulmonary capillary wedge pressure, bilirubin level, and Model for End-Stage Liver Disease-sodium score of 15 or higher were associated with increased risk of death.

CONCLUSION

Patients with PoPH who did not undergo LT had a poor prognosis. This persisted despite use of PAH-specific therapies and significant improvements in hemodynamics, echocardiography parameters of right ventricle function, 6-minute walk distance, and World Health Organization functional class.

The evolving landscape of pulmonary arterial hypertension clinical trials

Although it is a rare disease, the number of available therapeutic options for treating pulmonary arterial hypertension has increased since the late 1990s, with multiple drugs developed that are shown to be effective in phase 3 randomised controlled trials. Despite considerable advancements in pulmonary arterial hypertension treatment, prognosis remains poor. Existing therapies target pulmonary endothelial dysfunction with vasodilation and anti-proliferative effects. Novel therapies that target proliferative vascular remodelling and affect important outcomes are urgently needed. There is need for additional innovations in clinical trial design so that all emerging candidate therapies can be rigorously studied. Pulmonary arterial hypertension trial design has shifted from short-term submaximal exercise capacity as a primary endpoint, to larger clinical event-driven trial outcomes. Event-driven pulmonary arterial hypertension trials could face feasibility and efficiency issues in the future because increasing sample sizes and longer follow-up durations are needed, which would be problematic in such a rare disease. Enrichment strategies, innovative and alternative trial designs, and novel trial endpoints are potential solutions that could improve the efficiency of future pulmonary arterial hypertension trials while maintaining robustness and clinically meaningful evidence.

Risk stratification in adult and pediatric pulmonary arterial hypertension: A systematic review

Introduction

Currently, risk stratification is the cornerstone of determining treatment strategy for patients with pulmonary arterial hypertension (PAH). Since the 2015 European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines for the diagnosis and treatment of pulmonary hypertension recommended risk assessment, the number of studies reporting risk stratification has considerably increased. This systematic review aims to report and compare the variables and prognostic value of the various risk stratification models for outcome prediction in adult and pediatric PAH.

Methods

A systematic search with terms related to PAH, pediatric pulmonary hypertension, and risk stratification was performed through databases PubMed, EMBASE, and Web of Science up to June 8, 2022. Observational studies and clinical trials on risk stratification in adult and pediatric PAH were included, excluding case reports/series, guidelines, and reviews. Risk of bias was assessed using the Prediction model Risk Of Bias Assessment Tool. Data on the variables used in the models and the predictive strength of the models given by c-statistic were extracted from eligible studies.

Results

A total of 74 studies were eligible for inclusion, with this review focusing on model development (n = 21), model validation (n = 13), and model enhancement (n = 9). The variables used most often in current risk stratification models were the non-invasive WHO functional class, 6-minute walk distance and BNP/NT-proBNP, and the invasive mean right atrial pressure, cardiac index and mixed venous oxygen saturation. C-statistics of current risk stratification models range from 0.56 to 0.83 in adults and from 0.69 to 0.78 in children (only two studies available). Risk stratification models focusing solely on echocardiographic parameters or biomarkers have also been reported.

Conclusion

Studies reporting risk stratification in pediatric PAH are scarce. This systematic review provides an overview of current data on risk stratification models and its value for guiding treatment strategies in PAH.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022316885], identifier [CRD42022316885].

Plasma Cell-Free DNA Predicts Survival and Maps Specific Sources of Injury in Pulmonary Arterial Hypertension

BACKGROUND

Cell-free DNA (cfDNA) is a noninvasive marker of cellular injury. Its significance in pulmonary arterial hypertension (PAH) is unknown.

METHODS

Plasma cfDNA was measured in 2 PAH cohorts (A, n=48; B, n=161) and controls (n=48). Data were collected for REVEAL 2.0 (Registry to Evaluate Early and Long-Term PAH Disease Management) scores and outcome determinations. Patients were divided into the following REVEAL risk groups: low (≤6), medium (7-8), and high (≥9). Total cfDNA concentrations were compared among controls and PAH risk groups by 1-way analysis of variance. Log-rank tests compared survival between cfDNA tertiles and REVEAL risk groups. Areas under the receiver operating characteristic curve were estimated from logistic regression models. A sample subset from cohort B (n=96) and controls (n=16) underwent bisulfite sequencing followed by a deconvolution algorithm to map cell-specific cfDNA methylation patterns, with concentrations compared using t tests.

RESULTS

In cohort A, median (interquartile range) age was 62 years (47-71), with 75% female, and median (interquartile range) REVEAL 2.0 was 6 (4-9). In cohort B, median (interquartile range) age was 59 years (49-71), with 69% female, and median (interquartile range) REVEAL 2.0 was 7 (6-9). In both cohorts, cfDNA concentrations differed among patients with PAH of varying REVEAL risk and controls (analysis of variance P≤0.002) and were greater in the high-risk compared with the low-risk category (P≤0.002). In cohort B, death or lung transplant occurred in 14 of 54, 23 of 53, and 35 of 54 patients in the lowest, middle, and highest cfDNA tertiles, respectively. cfDNA levels stratified as tertiles (log-rank: P=0.0001) and REVEAL risk groups (log-rank: P<0.0001) each predicted transplant-free survival. The addition of cfDNA to REVEAL improved discrimination (area under the receiver operating characteristic curve, 0.72-0.78; P=0.02). Compared with controls, methylation analysis in patients with PAH revealed increased cfDNA originating from erythrocyte progenitors, neutrophils, monocytes, adipocytes, natural killer cells, vascular endothelium, and cardiac myocytes (Bonferroni adjusted P<0.05). cfDNA concentrations derived from erythrocyte progenitor cells, cardiac myocytes, and vascular endothelium were greater in patients with PAH with high-risk versus low-risk REVEAL scores (P≤0.02).

CONCLUSIONS

Circulating cfDNA is elevated in patients with PAH, correlates with disease severity, and predicts worse survival. Results from cfDNA methylation analyses in patients with PAH are consistent with prevailing paradigms of disease pathogenesis.

Incorporation of noninvasive assessments in risk prediction for pulmonary arterial hypertension

Risk assessment for pulmonary arterial hypertension (PAH) utilizing noninvasive prognostic variables could be more practical in real-world scenarios, especially at follow-up reevaluations. Patients who underwent comprehensive evaluations both at baseline and at follow-up visits were enrolled. The primary endpoint was all-cause mortality. Predictive variables identified by Cox analyses were further incorporated with the French noninvasive risk prediction approach. A total of 580 PAH patients were enrolled. During a median follow-up time of 47.0 months, 112 patients (19.3%) died. By multivariate Cox analyses, tricuspid annular plane systolic excursion (TAPSE), TAPSE/pulmonary arterial systolic pressure (PASP), and cardiopulmonary exercise testing-derived peak oxygen consumption (VO2) remained independent predictors for survival. Regarding the French noninvasive risk prediction method, substituting N-terminal pro-b-type natriuretic peptide (NT-proBNP) with the newly derived low-risk criteria of a TAPSE ≥ 17 mm or a TAPSE/PASP > 0.17 mm/mmHg, or alternating 6-min walking distance with a peak VO2 ≥ 44 %predicted retained the discrimination power. When recombining the low-risk criteria, the combination of World Health Organization functional class (WHO FC), TAPSE and peak VO2 at baseline, and the combination of WHO FC, NT-proBNP, and peak VO2 at follow-up showed better discriminative ability than the other combinations. In conclusion, Peak VO2, TAPSE, and TAPSE/PASP are significant prognostic predictors for survival in PAH, with incremental prognostic value when incorporated with the French noninvasive risk prediction approach, especially at reevaluations. For better risk prediction, WHO FC, at least one measurement of exercise capacity and one measurement of right ventricular function should be considered.

Prognostic value of brain natriuretic peptides in patients with pulmonary arterial hypertension: A systematic review and meta-analysis

BACKGROUND

Multiple biomarkers have been investigated in the risk stratification of patients with pulmonary arterial hypertension (PAH). This systematic review and meta-analysis is the first to investigate the prognostic value of (NT-pro)BNP in patients with PAH.

METHODS

A systematic literature search was performed using MEDLINE, Embase, Web of Science, the Cochrane Library and Google scholar to identify studies on the prognostic value of baseline (NT-pro)BNP levels in PAH. Studies reporting hazard ratios (HR) for the endpoints mortality or lung transplant were included. A random effects meta-analysis was performed to calculate the pooled HR of (NT-pro)BNP levels at the time of diagnosis. To account for different transformations applied to (NT-pro)BNP, the HR was calculated for a 2-fold difference of the weighted mean (NT-pro)BNP level of 247 pmol/L, for studies reporting a HR based on a continuous (NT-pro)BNP measurement.

RESULTS

Sixteen studies were included, representing 6999 patients (mean age 45.2-65.0 years, 97.3% PAH). Overall, 1460 patients reached the endpoint during a mean follow-up period between 1 and 10 years. Nine studies reported HRs based on cut-off values. The risk of mortality or lung transplant was increased for both elevated NT-proBNP and BNP with a pooled HR based on unadjusted HRs of 2.75 (95%-CI: 1.86-4.07) and 3.87 (95% CI 2.69-5.57) respectively. Six studies reported HRs for (NT-pro)BNP on a continues scale. A 2-fold difference of the weighted mean NT-proBNP resulted in an increased risk of mortality or lung transplant with a pooled HR of 1.17 (95%-CI: 1.03-1.32).

CONCLUSIONS

Increased levels of (NT-pro)BNP are associated with a significantly increased risk of mortality or lung transplant in PAH patients.

Risk Stratification of Patients with Pulmonary Arterial Hypertension: The Role of Echocardiography

Background: Given the morbidity and mortality associated with pulmonary arterial hypertension (PAH), risk stratification approaches that guide therapeutic management have been previously employed. However, most patients remain in the intermediate-risk category despite initial therapy. Herein, we sought to determine whether echocardiographic parameters could improve the risk stratification of intermediate-risk patients. Methods: Prevalent PAH patients previously enrolled in observational studies at 3 pulmonary hypertension centers were included in this study. A validated PAH risk stratification approach was used to stratify patients into low-, intermediate-, and high-risk groups. Right ventricular echocardiographic parameters were used to further stratify intermediate-risk patients into intermediate-low- and intermediate-high-risk groups based on transplant-free survival. Results: From a total of 146 patients included in our study, 38 patients died over a median follow-up of 2.5 years. Patients with intermediate-/high-risk had worse echocardiographic parameters. Tricuspid annular plane systolic excursion (TAPSE) and the degree of tricuspid regurgitation (TR) were highly associated with survival (p < 0.01, p = 0.04, respectively) and were subsequently used to further stratify intermediate-risk patients. Among intermediate-risk patients, survival was worse for patients with TAPSE < 19 mm compared to those with TAPSE ≥ 19 mm (estimated one-year survival 74% vs. 96%, p < 0.01) and for patients with moderate/severe TR compared to those with no/trace/mild TR (estimated one-year survival 70% vs. 93%, p < 0.01). Furthermore, among intermediate-risk patients, those with both TAPSE < 19 mm and moderate/severe TR had an estimated one-year survival (56%) similar to that of high-risk patients (56%), and those with both TAPSE ≥ 19 mm and no/trace/mild TR had an estimated one-year survival (97%) similar to that of low-risk patients (95%). Conclusions: Echocardiography, a routinely performed, non-invasive imaging modality, plays a pivotal role in discriminating distinct survival phenotypes among prevalent intermediate-risk PAH patients using TAPSE and degree of TR. This can potentially help guide subsequent therapy.

COMPERA 2.0: a refined four-stratum risk assessment model for pulmonary arterial hypertension

BACKGROUND

Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a three-stratum model to categorise risk as low, intermediate or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on four risk categories, with intermediate risk subdivided into intermediate-low and intermediate-high risk.

METHODS

We analysed data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on World Health Organization functional class, 6-min walk distance (6MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed using Kaplan-Meier analyses, log-rank testing and Cox proportional hazards models.

RESULTS

Data from 1655 patients with PAH were analysed. Using the three-stratum model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined four-stratum risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the three-stratum model and in 49.2% with the four-stratum model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk.

CONCLUSIONS

Modified risk stratification using a four-stratum model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original three-stratum model.

Clinical application of risk assessment in PAH: Expert center APRN recommendations

Performing longitudinal and consistent risk assessments for patients with pulmonary arterial hypertension (PAH) is important to help guide treatment decisions to achieve early on and maintain a low-risk status and improve patient morbidity and mortality. Clinical gestalt or expert perception alone may over or underestimate a patient's risk status. Indeed, regular and continued use of validated risk assessment tools more accurately predict patients' survival. Effective PAH risk assessments are often underutilized even though many seasoned clinicians will attest to using these tools routinely. We present recommendations based on real-world experience in varied clinical practice settings around the United States for overcoming barriers to facilitate regular, serial formal risk assessment. Expert advanced practice provider clinicians from mid to large-size medical centers collaborated to formulate recommendations based on multiple discourses and discussions. Enlisting the help of support staff, such as medical assistants and nurses, to fill in available risk parameters in risk assessment tools can save time for providers and increase efficiency, as can technology-based solutions such as integrating risk assessments into electronic medical records. Modified, abbreviated risk assessment tools can be applied to a patient's clinical scenario when all of a patient's data are not available to complete a more comprehensive assessment. Initial discussions regarding the overall meaning and prognostic importance of risk scores may assist patients to take on a more active role in terms of informed decision-making regarding their care. A collaborative approach can help clinics establish consistent use of risk assessment.

The role of serial right heart catheterization in risk stratification and management of pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial blood pressure secondary to increased pulmonary vascular resistance.

AREAS COVERED

Invasive hemodynamic assessment by heart catheterization (RHC) remains the gold standard to confirm the diagnosis, to determine the severity of right ventricular dysfunction and to test for pulmonary vasoreactivity. After diagnosis and initiation of therapy, many PAH centers continue to perform RHC at regular intervals to monitor for disease progression and alter management. We discuss the importance of risk stratification in PAH, the role of RHC in the evaluation and treatment of these patients and compare non-invasive risk assessment tools to that of RHC.

EXPERT OPINION

RHC is useful for diagnosis of PAH, assessing the risk of mortality and morbidity, directing the escalation and de-escalation of therapy, and monitoring for disease progression. In the current era of improved non-invasive cardiac hemodynamic assessment, the role for routine follow-up serial RHC in patients with PAH needs to be reassessed in future studies. With the availability of non-invasive risk assessment tools such as REVEAL Lite 2, it may be reasonable to reconsider the role of annual or protocoled RHC, and instead, move on to an "as needed" and individual approach.

Temporal trends in pulmonary arterial hypertension: results from the COMPERA registry

BACKGROUND

Since 2015, the European pulmonary hypertension guidelines recommend the use of combination therapy in most patients with pulmonary arterial hypertension (PAH). However, it is unclear to what extent this treatment strategy is adopted in clinical practice and if it is associated with improved long-term survival.

METHODS

We analysed data from COMPERA, a large European pulmonary hypertension registry, to assess temporal trends in the use of combination therapy and survival of patients with newly diagnosed PAH between 2010 and 2019. For survival analyses, we looked at annualised data and at cumulated data comparing the periods 2010-2014 and 2015-2019.

RESULTS

A total of 2531 patients were included. The use of early combination therapy (within 3 months after diagnosis) increased from 10.0% in patients diagnosed with PAH in 2010 to 25.0% in patients diagnosed with PAH in 2019. The proportion of patients receiving combination therapy 1 year after diagnosis increased from 27.7% to 46.3%. When comparing the 2010-2014 and 2015-2019 periods, 1-year survival estimates were similar (89.0% (95% CI 87.2-90.9%) and 90.8% (95% CI 89.3-92.4%), respectively), whereas there was a slight but nonsignificant improvement in 3-year survival estimates (67.8% (95% CI 65.0-70.8%) and 70.5% (95% CI 67.8-73.4%), respectively).

CONCLUSIONS

The use of combination therapy increased from 2010 to 2019, but most patients still received monotherapy. Survival rates at 1 year after diagnosis did not change over time. Future studies need to determine if the observed trend suggesting improved 3-year survival rates can be confirmed.

Development and evaluation of a predictive algorithm for unsatisfactory response among patients with pulmonary arterial hypertension using health insurance claims data

OBJECTIVE

This study aimed to develop and validate a predictive algorithm for unsatisfactory response to initial pulmonary arterial hypertension (PAH) therapy using health insurance claims.

METHODS

Adult patients with PAH initiated on a first PAH therapy (index date) were identified from Optum's de-identified Clinformatics Data Mart Database (1/1/2010-12/31/2019). A random survival forest algorithm was developed using patient-month data and predicted the "survival function" (i.e. risk of not having unsatisfactory response) over time. For each patient-month observation, risk factors were assessed in the 12 months prior. Unsatisfactory response was defined as the first instance of (1) new PAH therapy, (2) PAH-related hospitalization or emergency room visit, (3) lung transplant or atrial septostomy, (4) PAH-related death or (5) chronic oxygen therapy initiation. To facilitate use in clinical practice, a simplified risk score was also developed based on a linear combination of the most important risk factors identified in the algorithm.

RESULTS

In total, 4781 patients were included (median age = 69.0 years; 58.6% female). Over a median follow-up of 14.0 months, 3169 (66.3%) had an unsatisfactory response. The most important risk factors included in the algorithm were healthcare resource use (i.e. PAH-related outpatient visits, pulmonologist visits, cardiologist visits, all-cause hospitalizations), time since first PAH diagnosis, time since index date, Charlson Comorbidity Index, dyspnea, and age. Predictive accuracy was good for the full algorithm (C-statistic: 0.732) but was slightly lower for the simplified risk score (C-statistic: 0.668).

CONCLUSION

The present claims-based algorithm performed well in predicting time to unsatisfactory response following initial PAH therapy.

Risk assessment tools for survival prognosis: An era of new surrogacy endpoints for clinical outcome measurement in pulmonary arterial hypertension clinical trials?

Developing a new medication in a rare disease indication like pulmonary arterial hypertension (PAH) is very challenging. This is especially true now that clinical trials often employ time to clinical worsening (TTCW) as an endpoint (thus requiring a relatively large and lengthy trial) and since patients are more frequently prescribed combination therapy. During the last few decades, several tools have been developed to predict mortality in PAH and have demonstrated generally good discrimination. The objective of this review article is to assess the available data on the different tools and methods described in the literature and identify potential candidates that could be used as surrogate endpoints in pivotal randomized clinical trials in future. Some of these tools have been validated in various registries and in post-hoc analyses of clinical trial data, but none have been assessed in a prospective clinical trial and we still lack the evidence necessary for endorsement by health authorities. In this review, we identify several promising options that warrant further investigation as potential surrogate endpoints in clinical trials to replace TTCW or 6-minute walk distance. Prospective inclusion of such tools in new clinical trials may help build a stronger surrogacy for prognosis of disease progression and mortality.

Harnessing Big Data to Advance Treatment and Understanding of Pulmonary Hypertension

Pulmonary hypertension is a complex disease with multiple causes, corresponding to phenotypic heterogeneity and variable therapeutic responses. Advancing understanding of pulmonary hypertension pathogenesis is likely to hinge on integrated methods that leverage data from health records, imaging, novel molecular -omics profiling, and other modalities. In this review, we summarize key data sets generated thus far in the field and describe analytical methods that hold promise for deciphering the molecular mechanisms that underpin pulmonary vascular remodeling, including machine learning, network medicine, and functional genetics. We also detail how genetic and subphenotyping approaches enable earlier diagnosis, refined prognostication, and optimized treatment prediction. We propose strategies that identify functionally important molecular pathways, bolstered by findings across multi-omics platforms, which are well-positioned to individualize drug therapy selection and advance precision medicine in this highly morbid disease.

Mortality in Pulmonary Arterial Hypertension in the Modern Era: Early Insights From the Pulmonary Hypertension Association Registry

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan-Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment-naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44-68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow-up time of 489 days (281-812 days). The 1-, 2-, and 3-year mortality was 8% (95% CI, 6%-10%), 16% (95% CI, 13%-19%), and 21% (95% CI, 17%-25%), respectively. When stratified into low-, intermediate-, and high-risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment-naïve patients, initial combination therapy was associated with better 1-year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19-0.95]; P=0.037). Conclusions Mortality in the intermediate- and high-risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

[Risk Stratification in Patients with Pulmonary Arterial Hypertension under Treatment - Results of Four German Centers]

Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). According to the current European guidelines the expected 1-year risk of mortality for PAH patients can be categorized as low, intermediate, or high, based on clinical, non-invasive and hemodynamic data.Data from 131 patients with incident PAH (age 64 ± 14) and frequent comorbidities (in 66.4 %) treated between 2016 and 2018 at 4 German PH centers were analyzed. At baseline, most patients were classified as intermediate risk (76 %), 13.8 % as high risk and only 9.9 % as low risk.During follow-up while on treatment after 12 ± 3 months (range 9-16 months) 64.9 % were still classified as intermediate risk (76 %), 14.4 % as high risk and 20.7 % as low risk.Survival at 12 and 24 months was 96 % and 82 % in the intermediate risk group, while only 89 % and 51 % of the high risk patients were alive at these time points. In contrast, all patients in the low risk category were alive at 24 months.Despite the availability of various treatment options for patients with PAH even in specialized centers only a minority of patients can be stabilized in the low risk group associated with a good outcome.

Real-world treatment patterns, healthcare resource utilization, and cost among adults with pulmonary arterial hypertension in the United States

Treatment for pulmonary arterial hypertension (PAH) has evolved over the past decade, including approval of new medications and growing evidence to support earlier use of combination therapy. Despite these changes, few studies have assessed real-world treatment patterns, healthcare resource utilization (HCRU), and costs among people with PAH using recent data. We conducted a retrospective cohort study using administrative claims from the HealthCore Integrated Research Database®. Adult members with claims for a PAH diagnosis, right heart catheterization, and who initiated PAH treatment (index date) between October 1, 2015 and November 30, 2020 were identified. Members had to be continuously enrolled in the health plan for 6 months before the index date (baseline) and ≥30 days after. Treatment patterns, HCRU, and costs were described. A total of 843 members with PAH (mean age 62.3 years, 64.2% female) were included. Only 21.0% of members received combination therapy as their first-line treatment, while most members (54.6%) received combination therapy as second-line treatment. All-cause HCRU remained high after treatment initiation with 58.0% of members having ≥1 hospitalization and 41.3% with ≥1 emergency room visit. Total all-cause costs declined from $15,117 per patient per month at baseline to $14,201 after treatment initiation, with decreased medical costs ($14,208 vs. $6,349) more than offsetting increased pharmacy costs ($909 vs. $7,852). In summary, despite growing evidence supporting combination therapy, most members with PAH initiated treatment with monotherapy. Total costs decreased following treatment, driven by a reduction in medical costs even with increases in pharmacy costs.

Rationale and design of a screening study to detect schistosomiasis-associated pulmonary hypertension in Ethiopia and Zambia

Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH) worldwide, but the prevalence and risk factors for schistosomiasis-associated PAH (SchPAH) development are not well understood. Schistosomiasis-associated hepatosplenic disease (SchHSD) is thought to be a major risk factor for PAH development. Herein, we describe our plans for prospectively screening SchHSD subjects for clinical evidence of PAH at two major academic medical centers and national referral hospitals in Addis Ababa, Ethiopia and Lusaka, Zambia. The screening study will primarily be conducted by echocardiography, in addition to clinical assessments. Plasma samples will be drawn and banked for subsequent analysis based on preclinical animal model rationale. If successful, this study will demonstrate feasibility of conducting prospective cohort studies of SchPAH screening in schistosomiasis-endemic regions of Africa, and provide initial data on clinic-based disease prevalence and potential mechanistic biomarkers underlying disease pathogenesis.

Utilization of Risk Assessment Tools in Management of PAH: A PAH Provider Survey

Pulmonary arterial hypertension (PAH) is a chronically progressive fatal disease. A goal‐oriented approach to achieve low risk status has been associated with improved survival. A variety of risk stratification tools are available, but use is low. We conducted a survey to assess potential reasons for under‐utilization. We conducted a survey‐based study of global PAH disease specialists with a goal of assessing risk assessment utilization and identifying modifiable barriers to use. The survey was designed by the American College of Chest Physicians’ Pulmonary Vascular Diseases (PVD) NetWork. Respondents were global members of the PVD NetWork and Pulmonary Hypertension Association. Survey invitations were sent electronically to all members. Participation was anonymous and no provider or patient level data was collected. Participants from four countries responded with the majority (84%) being from the United States. Our survey found suboptimal use of any risk stratification tool with 71/112 (63%) reporting use. A total of 85% of the respondents had more than 5 years of experience in managing PAH. REVEAL 2.0 and European Society of Cardiology/European Respiratory Society risk tools were the most commonly used. A total of 44 (65%) surveyed felt that use of risk tools led to change in PAH therapies. Only 6 (9%) felt they prompted additional testing or changed the frequency of follow‐up. A total of 5 (7%) reported they prompted goals of care/palliative care discussions and 2 (3%) that they triggered lung transplant referral. The vast majority indicated that incorporation of risk tools into electronic medical records (EMR) would improve utilization. PAH risk assessment tools remain under‐utilized. Most respondents were experienced PAH clinicians. More than one‐third were not routinely using risk tools. Most felt that risk tools led to PAH therapy changes but few reported impacts on other aspects of care. The most commonly identified barriers to use were time constraints and lack of integration with EMR.

Characteristics, goal-oriented treatments and survival of pulmonary arterial hypertension in China: Insights from a national multicentre prospective registry

BACKGROUND AND OBJECTIVE

Nationally representative reports on the characteristics and long-term survival of pulmonary arterial hypertension (PAH) from developing countries are scarce. The applicability of the current main risk stratifications and the longitudinal changes in goal-oriented treatments have yet to be elucidated in real-world settings. Therefore, we aimed to provide insights into the characteristics, goal-oriented treatments and survival of PAH in China and to explore the applicability of the main risk stratifications in our independent cohort.

METHODS

PAH patients were consecutively enrolled from a national prospective multicentre registry. Data on baseline, follow-up re-evaluation and therapeutic changes were collected.

RESULTS

A total of 2031 patients were enrolled, with congenital heart disease (CHD)-PAH (45.2%) being the most common aetiology. The mean age was 35 ± 12 years, and 76.2% were females. At baseline, approximately 20% of the patients with intermediate or high risk received combination treatment. At follow-up, approximately half of the re-evaluated patients did not achieve low-risk profiles, and even among patients who received combination therapy at baseline, 4% of them still worsened. The rate of combination therapy increased significantly from 6.7% before 2015 to 35.5% thereafter. The main risk assessment tools demonstrated good performance for predicting survival both at baseline and at follow-up.

CONCLUSION

Chinese PAH patients show both similar and distinct features compared to other countries. Current main risk stratifications can significantly discriminate patients at different risk levels. There were still many patients not achieving low-risk profiles at follow-up, indicating more aggressive treatment should be implemented to optimize the goal-oriented treatment strategy.

Regular Risk Assessment in Pulmonary Arterial Hypertension - A Whistleblower for Hidden Disease Progression

Despite developments in the treatment of pulmonary arterial hypertension, timely treatment is seldom achieved, and hidden progression is not uncommonly disguised as a seemingly "stable" condition. Appropriate risk assessment tools facilitate goal-oriented treatment strategies. This article aimed to review the development of these risk assessment tools including early assessment equations/scores, European guidelines-based risk assessment scores, and tools derived from the United States nationwide registry. A stepwise and regular approach with these assessment tools in clinical practice is highly recommended for timely treatment escalation to stop disease progression early. In this review, a practical and recommended algorithm of these assessment tools is also provided.

E-REVEAL Lite 2.0 scoring for early prediction of disease progression in pulmonary arterial hypertension

Risk stratification is an essential tool in the management of pulmonary arterial hypertension (PAH). These tools lack detailed echocardiographic assessment which plays a central role in clinical risk assessment in PAH. Thus, we aimed at assessing whether adding echocardiography-driven data to REVEAL Lite 2.0 (Registry to Evaluate Early and Long-Term PAH Disease Management) improves the assessment of risk stratification in PAH. A retrospective analysis of 134 consecutive patients between January 2016 and December 2019 was done. We identified patients who experienced a disease progression "event" defined by the initiation of intravenous (IV) or parenteral prostacyclin, transplant referral, or death due to PAH. All other PAH patients who did not experience an "event" during this period were included in the analysis as controls. Echocardiography and REVEAL Lite 2.0 were collected from 4 to 8 months before the event and compared with the control group to predict the risk of a disease progression event. One hundred and ten patients were included in the final analysis with 22 experiencing a disease progression event and 88 remaining stable during the study period. Different echocardiographic parameters were combined with REVEAL Lite 2.0 scores in both groups. The combination of REVEAL Lite 2.0 and the left ventricular end-diastolic (LVED) eccentricity index (as a continuous variable) had the highest area under the curve (AUC) of 0.87, which approached a significant difference with that of the REVEAL Lite 2.0 alone (p = 0.052). An additional multivariable regression model that included REVEAL Lite 2.0, LVED eccentricity index as a continuous variable, and RAP achieved the best AUC at 0.88 (0.80, 0.96), which was significantly different from that of the REVEAL Lite 2.0 alone (AUC 0.77 [0.66, 0.88]; p = 0.049). These results suggest that combining different echocardiographic parameters to REVEAL Lite 2.0 provides more statistically accurate risk predictions compared to REVEAL Lite 2.0 alone. A combination of LVED eccentricity index with REVEAL Lite 2.0 achieved the best AUC in predicting the event in our cohort.

Strategies for optimizing intravenous prostacyclin-analog therapy in patients with pulmonary arterial hypertension

INTRODUCTION

Intravenous prostacyclin-analogs (PCA, e.g. epoprostenol, treprostinil, iloprost) have become an essential part in the therapy of patients with pulmonary hypertension (PH), mainly pulmonary arterial hypertension (PAH). They show considerable differences in pharmacology. A combination therapy including intravenous drugs is regarded as the 'gold standard' in most of PAH patients.

AREAS COVERED

This review discusses and summarizes the studies and concepts on which this therapy is based. To date, intravenous prostacyclin-analogs are mainly administered when standard therapy fails to improve patients to low-risk status. However, preliminary data from uncontrolled studies suggest that an 'upfront triple' therapy including intravenous or subcutaneous prostacyclin-analogs could be preferable in selected patients.

EXPERT OPINION

Various IV PCA have been evaluated in the treatment of patients with PAH. Today, combination therapy is the 'gold standard' for the majority of patients. Intravenous PCA is recommended from functional class III onwards. Timing of its initiation is still a point of discussion. An escalation of therapy to IV or SC PCA is always necessary if a low-risk status cannot be achieved with other targeted therapies. Preliminary data suggest that selected patients could benefit from an 'upfront triple' therapy. Controlled studies on which such recommendation could be based are lacking.

Topic-Based, Recent Literature Review on Pulmonary Hypertension

Pulmonary hypertension is a complex condition but a relatively common manifestation of severe cardiopulmonary disease. By contrast, pulmonary arterial hypertension is uncommon and is more prevalent in young women. To better categorize patients and to guide clinical decision-making, 5 diagnostic groups and associated subgroups characterize the spectrum of disease. A multidisciplinary approach to evaluation and treatment is recommended by published guidelines and often entails referral to a designated pulmonary hypertension center. Several key publications during the last couple of years merit review. The PubMed database was searched for English-language studies and guidelines relating to pulmonary hypertension. The following terms were searched, alone and in combination: pulmonary hypertension, pulmonary arterial hypertension, portopulmonary hypertension, and chronic thromboembolic pulmonary hypertension. The focus was on those publications with new information on evaluation and management of pulmonary hypertension between January 1, 2019, and January 31, 2021. Of the subgroups, 2 were of particular interest for this review: portopulmonary hypertension and chronic thromboembolic pulmonary hypertension. Last, available data on the impact of the coronavirus disease 2019 pandemic and newer treatment agents in early trials were selectively reviewed. The review is therefore intended to serve as a practical, focused review of important topics germane to those clinicians caring for patients with pulmonary hypertension.

Risk assessment in pulmonary hypertension based on routinely measured laboratory parameters

BACKGROUND

γ-glutamyl transferase (GGT), the aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, and the neutrophil-to-lymphocyte ratio (NLR) are prognostic biomarkers in several cardiovascular diseases, but their relevance in pulmonary hypertension (PH) is not fully understood. We aimed to assess their prognostic value in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH).

METHODS

We retrospectively analyzed 731 incident patients with idiopathic PAH or CTEPH who entered the Giessen PH registry during 1993-2019. A risk stratification score based on GGT, AST/ALT ratio, and NLR tertiles was compared with a truncated version of the European Society of Cardiology/European Respiratory Society (ESC/ERS) risk stratification scheme. Associations with survival were evaluated using Kaplan-Meier and Cox regression analyses. External validation was performed in 311 patients with various types of PAH or CTEPH from a second German center.

RESULTS

GGT levels, AST/ALT, and NLR independently predicted mortality at baseline and during follow-up. The scoring system based on these biomarkers predicted mortality at baseline and during follow-up (both log-rank p < 0.001; hazard ratio [95% confidence interval], high vs low risk: baseline, 7.6 [3.9, 15.0]; follow-up, 13.3 [4.8, 37.1]). Five-year survival of low, intermediate, and high risk groups was 92%, 76%, and 51%, respectively, at baseline and 95%, 78%, and 50%, respectively, during follow-up. Our scoring system showed characteristics comparable to the ESC/ERS scheme, and predicted mortality in the validation cohort.

CONCLUSION

GGT, AST/ALT, and NLR were reliable prognostic biomarkers at baseline and during follow-up, with predictive power comparable to the gold standard for risk stratification.

COMPERA 2.0: A refined 4-strata risk assessment model for pulmonary arterial hypertension

Background

Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a three-stratum model to categorise risk as low, intermediate or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on four risk categories, with intermediate risk subdivided into intermediate-low and intermediate-high risk.

Methods

We analysed data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on World Health Organization functional class, 6-min walk distance (6MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed using Kaplan–Meier analyses, log-rank testing and Cox proportional hazards models.

Results

Data from 1655 patients with PAH were analysed. Using the three-stratum model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined four-stratum risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the three-stratum model and in 49.2% with the four-stratum model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk.

Conclusions

Modified risk stratification using a four-stratum model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original three-stratum model.

COMPERA 2.0, a four-stratum risk assessment model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically significant changes in risk than the original three-stratum modelhttps://bit.ly/3mzPKjA

External validation of a refined 4-strata risk assessment score from the French pulmonary hypertension Registry

Introduction

Contemporary risk assessment tools categorise patients with pulmonary arterial hypertension (PAH) as low, intermediate or high risk. A minority of patients achieve low risk status with most remaining intermediate risk. Our aim was to validate a four-stratum risk assessment approach categorising patients as low, intermediate-low, intermediate-high or high risk, as proposed by the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) investigators.

Methods

We evaluated incident patients from the French PAH Registry and applied a four-stratum risk method at baseline and at first reassessment. We applied refined cut-points for three variables: World Health Organization functional class, 6-min walk distance and N-terminal pro-brain natriuretic peptide. We used Kaplan–Meier survival analyses and Cox proportional hazards regression to assess survival according to three-stratum and four-stratum risk approaches.

Results

At baseline (n=2879), the four-stratum approach identified four distinct risk groups and performed slightly better than a three-stratum method for predicting mortality. Four-stratum model discrimination was significantly higher than the three-stratum method when applied during follow-up and refined risk categories among subgroups with idiopathic PAH, connective tissue disease-associated PAH, congenital heart disease and portopulmonary hypertension. Using the four-stratum approach, 53% of patients changed risk category from baseline compared to 39% of patients when applying the three-stratum approach. Those who achieved or maintained a low risk status had the best survival, whereas there were more nuanced differences in survival for patients who were intermediate-low and intermediate-high risk.

Conclusions

The four-stratum risk assessment method refined risk prediction, especially within the intermediate risk category of patients, performed better at predicting survival and was more sensitive to change than the three-stratum approach.

A four-stratum risk assessment method with low, intermediate-low, intermediate-high and high risk categories was better at discriminating survival in pulmonary arterial hypertension than a three-stratum method with low, intermediate and high risk groupshttps://bit.ly/3mA6kj7

Critical Care Management of Decompensated Right Heart Failure in Pulmonary Arterial Hypertension Patients - An Ongoing Approach

Despite substantial advancements in diagnosis and specific medical therapy in pulmonary arterial hypertension patients’ management, this condition continues to represent a major cause of mortality worldwide. In pulmonary arterial hypertension, the continuous increase of pulmonary vascular resistance and rapid development of right heart failure determine a poor prognosis. Against targeted therapy, patients inexorable deteriorate over time. Pulmonary arterial hypertension patients with acute right heart failure who need intensive care unit admission present a complexity of the disease pathophysiology. Intensive care management challenges are multifaceted. Awareness of algorithms of right-sided heart failure monitoring in intensive care units, targeted pulmonary hypertension therapies, and recognition of precipitating factors, hemodynamic instability and progressive multisystem organ failure requires a multidisciplinary pulmonary hypertension team. This paper summarizes the management strategies of acute right-sided heart failure in pulmonary arterial hypertension adult cases based on recently available data.

Change in REVEAL Lite 2 risk score predicts outcomes in patients with pulmonary arterial hypertension in the PATENT study

BACKGROUND

Risk assessment is essential in pulmonary arterial hypertension (PAH) management. We investigated the effect of riociguat on REVEAL Lite 2 score, an abridged version of the REVEAL risk score, and its association with long-term outcomes in PATENT.

METHODS

PATENT-1 was a randomized, double-blind study of riociguat vs placebo in patients with PAH. In the PATENT-2 open-label extension, all patients received riociguat up to 2.5 mg three times daily (n = 396). REVEAL Lite 2 scores were calculated at baseline, PATENT-1 Week 12, and PATENT-2 Week 12, with patients stratified as low- (1-5), intermediate- (6-7), or high-risk (≥8). Kaplan-Meier and Cox proportional hazards analyses assessed association of riociguat with survival and clinical worsening-free survival (CWFS).

RESULTS

REVEAL Lite 2 score improved with riociguat 2.5 mg at PATENT-1 Week 12 (least-squares mean difference vs placebo: -0.8; p = 0.0004). More patients receiving riociguat 2.5 mg stabilized or improved risk stratum at PATENT-1 Week 12 vs placebo (p = 0.0005) and achieved low-risk status. REVEAL Lite 2 score at baseline and PATENT-1 Week 12 were associated with survival and CWFS (all p < 0.0001), as was change in score from baseline to Week 12 (p = 0.0002 and p < 0.0001, respectively). Survival and CWFS differed between risk strata at baseline (p < 0.0001) and PATENT-1 Week 12 (p < 0.0001).

CONCLUSIONS

This analysis confirms the risk-reduction benefits of riociguat in patients with PAH and further contributes to the validation of REVEAL Lite 2 in facilitating PAH risk assessment.

Dominating Cause of Pulmonary Hypertension May Change Over Time-Diagnostic and Therapeutic Considerations in a Patient with Pulmonary Hypertension Due to Rheumatoid Arthritis with Lung Involvement

Chronic lung diseases are one of the most frequent causes of pulmonary hypertension (PH). The diagnostic challenge is to differentiate PH due to chronic lung disease from pulmonary arterial hypertension (PAH) with coexisting chronic lung disease. Moreover, the dominating cause of PH may change over time, requiring the implementation of new diagnostic procedures and new treatment modalities. We present a 68-year-old female, initially diagnosed with PH in the course of interstitial lung disease, with restrictive impairment of lung function. Therapy with immunosuppressive drugs resulted in significant clinical, radiological and functional improvement. However, five years later, arthritis symptoms developed, with PH worsening, despite stable lung disease. The patient was diagnosed with PAH in the course of rheumatoid arthritis. The introduction of sildenafil resulted in marked clinical and hemodynamic responses. Long-term survival (eleven years from PH onset and five years from PAH confirmation) has been achieved, and the patient remains in good functional condition. As the differential diagnosis of PH in patients with lung diseases is complex, the cooperation of pulmonologists and cardiologists is mandatory to obtain therapeutic success.

Facemasks and Walk Distance in Pulmonary Arterial Hypertension Patients

Little is known about the effect of wearing a facemask on the physiological and perceptual responses to exercise in patients with pulmonary arterial hypertension (PAH). We performed a single-center retrospective study to evaluate whether facemask wearing impacted distanced covered, rating of perceived exertion (RPE), and arterial oxygen saturation (SpO₂) during a 6-minute walk test (6MWT) in PAH patients. Forty-five patients being treated for group 1 PAH and who performed a 6MWT before and after implementation of a facemask mandate were included in the analysis. Each included patient performed a 6MWT without (test 1) and with (test 2) a facemask between October 1, 2019, and October 31, 2020. At both time points, all patients also underwent a submaximal cardiopulmonary exercise test, echocardiogram, and blood laboratory tests, with a Registry to Evaluate Early and Long-Term PAH Disease Management Lite 2.0 score calculated. The two 6MWTs were performed 81±51 days apart, and all patients were clinically stable at both testing timepoints. Six-minute walk test distance was not different between test 1 and test 2 (405±108 m vs 400±103 m, P=.81). Similarly, both end-test RPE and lowest SpO₂ during the 6MWT were not different in test 1 and test 2 (RPE: 2.5±1.7 vs 2.5±2.1, P=.91; SpO₂ nadir: 92.8±3.4% vs 93.3±3.3%, P=.55). Our findings show that wearing a facemask has no discernable impact on the arterial oxygen saturation and perceptual responses to exercise or exercise capacity in patients with moderate-to-severe PAH. This study reinforces the evidence that wearing a facemask is safe in PAH patients, even during exercise.

Pulmonary Arterial Hypertension: Diagnosis, Treatment, and Novel Advances

The diagnosis and management of pulmonary arterial hypertension (PAH) includes several advances, such as a broader recognition of extrapulmonary vascular organ system involvement, validated point-of-care clinical assessment tools, and focus on the early initiation of multiple pharmacotherapeutics in appropriate patients. Indeed, a principal goal in PAH today is an early diagnosis for prompt initiation of treatment to achieve a minimal symptom burden; optimize the patient's biochemical, hemodynamic, and functional profile; and limit adverse events. To accomplish this end, clinicians must be familiar with novel risk factors and the revised hemodynamic definition for PAH. Fresh insights into the role of developmental biology (i.e., perinatal health) may also be useful for predicting incident PAH in early adulthood. Emergent or underused approaches to PAH management include a novel TGF-β ligand trap pharmacotherapy, remote pulmonary arterial pressure monitoring, next-generation imaging using inert gas-based magnetic resonance and other technologies, right atrial pacing, and pulmonary arterial denervation. These and other PAH state of the art advances are summarized here for the wider pulmonary medicine community.

Short-Term Impact of Iron Deficiency in Different Subsets of Patients with Precapillary Pulmonary Hypertension from an Eastern European Pulmonary Hypertension Referral Center

Background

Over the last few decades, interest in the role of iron status in pulmonary hypertension (PH) has grown considerably due to its potential impact on symptoms, exercise capacity (as assessed by the 6-minute walk distance [6MWD]), prognosis, and mortality. The aim of the present study was to identify iron deficiency (ID) prevalence in specific precapillary PH subgroups of Romanian patients and its short-term impact on 6MWD.

Patients and Methods

Complete datasets from 25 precapillary PH adults were examined and included in the analysis. Data were collected at baseline and after continuous follow-up of an average of 13.5 months. Enrolled patients were assigned to group 1 (pulmonary arterial hypertension) or subgroup 4.1 (chronic thromboembolic pulmonary hypertension), and individualized targeted therapy was prescribed. General characteristics, World Health Organization functional class, 6MWD, pulse oximetry, laboratory parameters, and echocardiographic and hemodynamic parameters were recorded. Ferritin values and transferrin saturation were used to assess ID.

Results

At baseline, 16 out of 25 patients were iron deficient. The univariate linear regression analysis did not show a statistically significant impact of ID on 6MWD (p=0.428). In multivariate regression analysis, possible predictors of 6MWD, including ID, were not statistically significant at baseline or after an average of 13.5 months follow-up (p=0.438, 0.361, respectively) and ID indicates a negative impact on 6MWD independent of applied corrections.

Conclusion

The results of this study demonstrate that 1.4.1 subgroup PAH patients have an increased prevalence of ID compared with other etiologies. ID has a negative impact on the functional status (assessed by 6MWD), in specific groups and subgroups of patients with precapillary PH, albeit not independently nor significant to other known predictors such as age, gender, oxygen saturation, and hemoglobin value. These data can be integrated with global research and are consistent with phenotypes of patients diagnosed with PH of different etiologies.

What's new in pulmonary hypertension clinical research: lessons from the best abstracts at the 2020 American Thoracic Society International Conference

In this conference paper, we review the 2020 American Thoracic Society International Conference session titled, "What's New in Pulmonary Hypertension Clinical Research: Lessons from the Best Abstracts". This virtual mini-symposium took place on 21 October 2020, in lieu of the annual in-person ATS International Conference which was cancelled due to the COVID-19 pandemic. Seven clinical research abstracts were selected for presentation in the session, which encompassed five major themes: (1) standardizing diagnosis and management of pulmonary hypertension, (2) improving risk assessment in pulmonary arterial hypertension, (3) evaluating biomarkers of disease activity, (4) understanding metabolic dysregulation across the spectrum of pulmonary hypertension, and (5) advancing knowledge in chronic thromboembolic pulmonary hypertension. Focusing on these five thematic contexts, we review the current state of knowledge, summarize presented research abstracts, appraise their significance and limitations, and then discuss relevant future directions in pulmonary hypertension clinical research.

The Evolution of Risk Assessment in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic debilitating disease that carries an unacceptably high morbidity and mortality rate despite improved survival with modern therapies. The combination of several modifiable and nonmodifiable variables yields a robust risk assessment across various available clinical calculators. The role of risk calculation is integral to managing PAH and aids in the timely referral to expert centers and potentially lung transplantation. Studies are ongoing to determine the role of risk calculators in the framework of clinical trials and to elucidate novel markers of high risk in PAH.

Right ventricular expression of NT-proBNP adds predictive value to REVEAL score in patients with pulmonary arterial hypertension

Aims

The Registry to Evaluate Early and Long‐Term PAH Disease Management (REVEAL) risk scores differentiate survivals in patients with pulmonary arterial hypertension (PAH). However, measurements of N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) in the peripheral blood may not adequately reflect early‐stage decompensated heart failure (HF). Given that right heart catheterization (RHC) can facilitate measurements of intracardiac NT‐proBNP, in this study our aim was to evaluate the predictive role of right ventricular (RV) NT‐proBNP measurements in patients with PAH.

Methods and results

We prospectively collected intracardiac blood samples for NT‐proBNP measurements from patients diagnosed with World Health Organization Group I PAH during RHC. Clinical information including the aetiology of PAH (idiopathic, connective tissue disease, or congenital heart disease) and REVEAL scores were recorded. The primary endpoint was hospitalization for decompensated HF; median duration of follow‐up was 28 months. Among the 62 patients evaluated, 12 reached the designated endpoint. REVEAL risk scores were higher among patients hospitalized for HF. We detected no significant differences in plasma NT‐proBNP levels in peripheral circulation, in the right atrium, or in pulmonary arterial blood; however, significantly higher levels of NT‐proBNP were detected in the RV in patients diagnosed with PAH. RV NT‐proBNP was a sensitive predictor (cut‐off value 1500 pg/mL) of subsequent hospitalization for HF. Our findings indicate that RV NT‐proBNP levels add predictive value to REVEAL scores with respect to future hospitalization due to HF.

Conclusions

Right ventricular NT‐proBNP levels combined with REVEAL 2.0 could predict the development of subsequent HF in patients with PAH and may be a potential biomarker.

Risk assessment in precapillary pulmonary hypertension: a comparative analysis

Background

Risk stratification is essential to assess mortality risk and guide treatment in patients with precapillary pulmonary hypertension (PH). We herein compared the accuracy of different currently used PH risk stratification tools and evaluated the significance of particular risk parameters.

Methods

We conducted a retrospective longitudinal observational cohort study evaluating seven different risk assessment approaches according to the current PH guidelines. A comprehensive assessment including multi-parametric risk stratification was performed at baseline and 4 yearly follow-up time-points. Multi-step Cox hazard analysis was used to analyse and refine risk prediction.

Results

Various available risk models effectively predicted mortality in patients with precapillary pulmonary hypertension. Right-heart catheter parameters were not essential for risk prediction. Contrary, non-invasive follow-up re-evaluations significantly improved the accuracy of risk estimations. A lack of accuracy of various risk models was found in the intermediate- and high-risk classes. For these patients, an additional evaluation step including assessment of age and right atrium area improved risk prediction significantly.

Discussion

Currently used abbreviated versions of the ESC/ERS risk assessment tool, as well as the REVEAL 2.0 and REVEAL Lite 2 based risk stratification, lack accuracy to predict mortality in intermediate- and high-risk precapillary pulmonary hypertension patients. An expanded non-invasive evaluation improves mortality risk prediction in these individuals.